Present invention relates to an image sensing apparatus and method for image-sensing an object such as original document.
FIG. 40 is a perspective view showing the configuration of an image sensing system using a conventional image sensing apparatus. In FIG. 40, reference numeral 100 denotes an image sensing system comprising an image input unit 101 and a video monitor 102 connected to the image input unit 101. The image input unit 101 has a camera lens 103, a frame 104 supporting the camera lens 103 and a base 106 on which an original 105 as an object is placed. Further, the image input unit 101 has an operation panel 107 at the front portion. The operation panel 107 has a power switch for the image input unit, a zoom button for adjustment of field of view, a focus button for auto/manual focusing (all not shown) and so on. The base 106 has marks 108 at the four corners indicating an image sensing area of the camera lens 103. The image sensing area is set to be somewhat larger than the wide-end (position of a zoom ring when the focal distance of a zoom lens is the longest) image sensing area. The video monitor 102 displays an image of an object such as the original 105 placed on the base 106 on an image screen 109.
Next, the operation procedure for the image sensing system 100 in FIG. 40 will be described. When the system is used, the power switch is turned on (ON) to make the system active. At this time, white balance is automatically adjusted, autofocusing of the camera lens 103 is made, and the field of view is adjusted for wide-end (position of zoom ring when the focal length of zoom lens is the shortest) image sensing. Then, a user sets the original as the object for image sensing on about the center of the base 106. At this time, the user determines the position on the base 106 where the original 105 is placed, from the marks 108 printed on the base 106. If necessary, the user manipulates the zoom button to change the size (field of view) of the original 105 displayed on the image screen 109 of the video monitor 102. Also, if necessary, the user manipulates the focus button to adjust focusing.
As described above, in the conventional system, the image sensing area for image-sensing the original 105 by the camera lens 103 is indicated by the marks 108 printed on the four corners of the base 106. However, such image sensing area indicating means has the following problems:
(1) If the size of the original 105 is larger than the image sensing area indicated by the marks 108, the marks 108 are hidden by the original 105, whereby it is difficult to determine the portion of the original to be sensed. PA1 (2) If the size of the original 105 is smaller than the image sensing area indicated by the marks 108, a correct image sensing area is not easily determined. PA1 (3) If the zooming function of the camera lens 103 is operated to change the size of the original 105 displayed on the image screen 109 of the video monitor 102, the image sensing area indicated by the marks 108 becomes improper for the image sensing, which disturbs correct determination of image sensing position.